New research finds benefits of whole grains to glucose metabolism

New research from the University of Eastern Finland reveals new findings on the cell level effects of a whole grain-rich diet. Published in the The American Journal of Clinical Nutrition, the study found that a high intake of whole grains increased the levels of betaine compounds in the body, resulting in improved glucose metabolism.

“We know that a high intake of whole grains protects against Type 2 diabetes and cardiovascular diseases,” said Kati Hanhineva, Ph.D., principal investigator of the study at the University of Eastern Finland and founder and chairman of Afekta Technologies. “Up until now, however, we haven't understood the cellular mechanisms through which a whole grain-rich diet impacts our body."

Over the course of 12 weeks, researchers investigated the effects of a whole grain-rich diet on mice and humans’ metabolites using metabolomics analysis. Mice were fed rye and wheat bran-rich foods or a high-fat diet while humans with characteristics of the metabolic syndrome were randomly assigned to either a whole grain-enriched or control diet.

Scientists found that eating more whole grains increased the levels of betaine compounds in both subjects. In particular, concentrations of pipecolic acid betaine and valine betaine were increased.

"This is the first time many of these betaine compounds were observed in the human body," noted Dr. Hanhineva. Researchers also observed a correlation between improved glucose metabolism.

During their investigation, the group discovered 5-aminovaleric acid betaine (5-AVAB), a betaine compound that resides in metabolically active tissues such as the heart.

The researchers observed that 5-AVAB reduced cardiac muscle cells’ use of fatty acids as an energy source by inhibiting the function of a certain cell membrane protein, said Olli Kärkkäinen, Ph.D., researcher at University of Eastern Finland.

"This cell level effect is similar to that of certain drugs used for cardiovascular diseases,” said Dr. Kärkkäinen. “However, it is important to keep in mind that we haven't proceeded beyond cell level experiments yet. We need further research in animals and humans to verify that 5-AVAB really can impact the function of our body."

Dr. Hanhineva said that the researchers will continue to examine the effects these compounds have on the human body and how intestinal microbes may contribute to the compound’s formation.